CN1256730A

CN1256730A - Multilayer forming fabric with stitchbonded yarn pairs woven into papermaking surface

Info

Publication number: CN1256730A
Application number: CN97182244A
Authority: CN
Inventors: 凯文·J·沃德
Original assignee: Weavexx LLC
Current assignee: Weavexx LLC
Priority date: 1997-08-01
Filing date: 1997-10-16
Publication date: 2000-06-14
Anticipated expiration: 2017-10-16
Also published as: AU4822197A; DE69712647T2; EP1021616B1; DE1021616T1; KR100508540B1; US5881764A; NO20000527D0; KR20010012470A; JP2003526016A; CA2288028C; EP1021616A1; BR9714814A; DE69712647D1; JP4018336B2; AU728680B2; CN1095010C; NZ500341A; NO20000527L; ATE217657T1; WO1999006630A1

Abstract

A multi-layer papermaker's forming fabric utilizes stitching yarns in the papermaking surface. The fabric of the present invention is comprised of a plurality of repeat units, each repeat unit including a set of top machine direction yarns, a set of bottom cross machine direction yarns interwoven with the set of bottom machine direction yarns, and a plurality of pairs of first and second stitching yarns extending in the cross machine direction. The first and second stitching yarns of each yarn pair are interwoven with the top and bottom machine direction yarns such that the fiber support portions of the first stitching yarns are interwoven with the top machine direction yarns, the fiber support portions of the second stitching yarns are positioned below the top machine direction yarns, and the fiber support portions of the second stitching yarns are interwoven with the top machine direction yarns, the fiber support portions of the first stitching yarns being positioned below the top machine direction yarns. The first and second stitching yarns cross each other as they pass under a machine direction transition top yarn, and each binding portion of the first and second stitching yarns passes under at least one machine direction bottom yarn. The fiber support portions of the stitching yarns and the top machine direction yarns form the papermaking surface.

Description

In papermaking surface, inweave the right multi-layer forming fabric of stitching yarn

The present invention relates to paper technology, specifically, relate to employed fabric in paper-making process.

In traditional fourdrinier wire paper technology, a kind of water slurry or suspended matter (being commonly called as paper pulp) of cellulose fibre to be sent on the end face of up section an of endless belt, this endless belt forms with wire and/or synthetic material braiding, and moves between two or more cylinders.This endless belt is commonly referred to as " forming fabric ", it has a papermaking surface that is positioned at up section upper surface of this fabric, a kind of effect of filter is played on this surface, makes cellulose fibre from being to separate the paper pulp of medium with water, thereby forms a kind of temperature gauze.Under the effect of the existing vacuum of gravity or up section lower surface place of fabric (promptly so-called " machine side "), moisture passes the eyelet of the forming fabric that is known as osculum and is discharged from.

After breaking away from forming part, gauze is sent to the press section of paper machine, and it passes the roll gap of being made up of one or more pairs of pressure rollers at this, and described pressure roller is covered by another kind of fabric, and this fabric is commonly referred to as " pressed felt ".The pressure of pressure roller is discharged redundant moisture from gauze; A kind of " felt " layer is set in pressed felt usually, is used for strengthening draining.Then paper web is sent into a drying section, so that further remove moisture.After the drying, paper web just can enter next step processing and pack.

In general, the fabric that paper machine is used is made into a kind of endless belt, and it is a kind of produced in two kinds of basic weaving technologies of utilization.In first kind of technology, use a kind of plain weave technology to weave a kind of plain cloth, use any one method of attachment of the prior art that its end is combined again, form a kind of endless belt, for example its end can be broken, and then it is woven into one (be referred to as usually splicing) again, and also it can be made on a flap that can carry out the pin seam or and make at the one end with a special flap tabs, then they are woven into again the endless belt that can carry out the pin seam.For a kind of paper machine plain cloth, its warp thread extends along machine direction, and weft yarn then is to extend along the direction perpendicular to machine.In second kind of technology, adopt a kind of endless woven technology fabric directly to be woven into a kind of form of endless belt.In this endless woven technology, warp thread is along extending perpendicular to machine direction, and weft yarn then extends along machine direction.At this, term " machine direction " (MD) (CMD) is represented a direction consistent with the direction of advance of this papermaker's fabric on paper machine respectively with " cross machine ", and surface that is parallel to this fabric and perpendicular to the direction of its traffic direction.Two kinds of above-mentioned methods are methods commonly known in the art, and " endless belt " described herein is meant the band made from above-mentioned any method.

The effective supporting of tissue layer, fiber and not form wire mark be the factor that will consider emphatically in paper-making process, especially all the more so for the forming part of paper machine, initial l Water Paper net is in this formation.When making high-grade paper, wire mark is the problem of a particular importance, because it is the character that influences paper, and a central factor of paper seal, porosity, light transmission and broken hole etc. for example.Wire mark is that the single fiber cellulose fiber is orientated, causes the end of fiber by chance to be positioned at the gap of the solid wire of forming fabric or yarn in paper web and forms.At this problem, people advise adopting coplanar, the transparent fabric construction in a kind of surface, and it allows the paper fiber to form bridge formation between adjacent fabric yarn, rather than passes the gap between the yarn.At this, " copline " vocabulary shows that the upper end of the yarn that forms the Web forming surface is located substantially on same height, thereby makes its surface present a kind of form that is roughly the plane.So, be used for the high-grade paper of purposes such as high-grade printing, carbonization, cigarette manufacture, capacitor, all be produced on the very fine forming fabric of weaving or becoming before this with very thin metal wire knitted.

Regrettably, the forming fabric of this meticulous braiding normally is highly brittle weak, and all lacks DIMENSIONAL STABILITY (especially in use) on machine direction and cross machine, causes the fabric shortening in service life thus.In addition, the meticulous drainage performance that might destroy fabric of weaving makes it to be not suitable for use in forming fabric.

In order to solve these problems relevant with meticulous braiding, people develop some multi-layer forming fabrics, and their paper molded surface has meticulous yarn net, is beneficial to the moulding of paper, at itself and the contacted side of machine then is coarse yarn net, so that enough intensity and durabilities to be provided.For example, include a tissue layer that mesh is closely knit in existing a kind of fabric, also have the tissue layer that mesh is coarse, also have some stitching yarns that these two tissue layer are combined.This kind fabric is commonly referred to as " three layers " fabric, describes to some extent in the United States Patent (USP) 5,437,315 of the United States Patent (USP) 5,152,326 of the United States Patent (USP) 4,501,303 of Osterberg, Vohringer and Ward.

Though these fabrics have obtained successful use, still there are some shortcomings in they, and these shortcomings are relevant with contained stitching yarn.In a kind of typical three formable layer fabrics, one or more stitching yarn are arranged between some top layers and bottom CMD yarn, and with top layer and bottom MD yarns interwoven together.In this structure, a part of stitching yarn has constituted a part of papermaking surface of this fabric.As a result, with the paper that this fabric is made, its outward appearance may be subjected to the influence (being negative effect sometimes) of stitching yarn.

In addition, confirmed already that treble cloths existed the interlayer wear problems.When this fabric is used on the paper machine, can misplace mutually between its top layer and the bottom, no matter be that machine direction or cross machine are all like this, this is because pressure roller causes the pulling force that fabric applied.This phenomenon for example is known as become on the paper machine of " high coiling " more serious in some paper machines, comprise a plurality of pressure rollers in these paper machines, and some pressure rollers wherein contact with the end face of fabric.This dislocation might cause the wearing and tearing of fabric, and its thickness is reduced, and influences the drainage of fabric thus, and the performance in paper-making process.In many cases, determined this just interlayer wearing and tearing in the service life of fabric, and be not the wearing and tearing with contacted this fabric machine side surface of paper machine.

In addition, to have a kind of different braidings flower type (be that they also interweave with the CMD bottom yarn simultaneously because the stitching yarn of this treble cloths is compared with its CMD top layer yarns, but the CMD top layer yarns is really not so), the tension force between stitching yarn and the CMD top layer yarns is also different.These differences can cause fabric to produce nonplanar distortion, and then reduce the quality of the paper of being produced by this fabric.

Simultaneously, the stitching yarn of this treble cloths is very solid and enduringly top layer and bottom is combined, with the opposing bottom in wearing and tearing and the scratch experienced contacted the time with paper machine, but want to produce high-quality paper, must be very meticulous.This balance is very difficult.

Be conceived to above problem, one object of the present invention is that a kind of multi-layer forming fabric structure is provided, and the distortion of its end face tissue layer is very little.

Another object of the present invention provides a kind of multi-layer forming fabric structure, and it can produce high-quality paper.

Another object of the present invention provides a kind of multi-layer forming fabric structure, and it can make and keep a kind of firm bonding state between top layer and the bottom.

Another object of the present invention provides a kind of multi-layer forming fabric structure, and it can solve the interlayer wear problems.

These problems and some otherly all solved by the present invention is gratifying the present invention relates to a kind of use for paper machine, multi-layer forming fabric of having used a kind of stitching yarn on its papermaking surface.Include many repetitives in the fabric of the present invention, each repetitive comprises: the top layer yarns of one group of machine direction; The bottom yarn of one group of machine direction; The bottom yarn of one group of cross machine, they and that are organized the bottom yarn weave in of machine direction; Also have some first and second stitching yarns to extending along cross machine.Each to first and second stitching yarns all with the top layer yarns and the bottom yarn weave in of machine direction, like this, fiber support in first stitching yarn part just with the top layer yarns weave in of machine direction, bound fraction in second stitching yarn then is positioned at the below of the top layer yarns of machine direction, and the top layer yarns weave in of the fiber support in second stitching yarn part and machine direction, the bound fraction in first stitching yarn then is positioned at the below of the top layer yarns of machine direction.When first and second stitching yarns when the below of a machine direction transition top layer yarns is passed, they intersect mutually.Each bound fraction of first and second stitching yarns all passes from the below of at least one machine direction bottom yarn.The top layer yarns of the fiber support of stitching yarn part and machine direction has formed papermaking surface, and in not passing the cross machine yarn of at least one machine direction bottom yarn, they have occupied below percent 33, preferably do not contain this yarn.In this structure, stitching yarn gets on to bottom being sewn onto the machine direction top layer yarns, and has formed the live part of papermaking surface.

In a preferred embodiment, the fiber support of stitching yarn part has formed a kind of tabby papermaking surface with the machine direction top layer yarns.In another preferred embodiment, they have formed 1 * 2 twill papermaking surface.In each case, the density of stitching yarn all is enough to each layer of fabric linked together firmly reliably.

Figure 1A is the top view that the present invention 20 combines an embodiment of multi-layer forming fabric, and this fabric has a plain weave top surface.

Figure 1B is a top cutaway view of fabric basal surface shown in Figure 1.

Fig. 2 A-2J is the cutaway view of the stitching yarn in the fabric shown in Figure 1A and the 1B.

Fig. 3 A is the top view that the present invention 24 combines an embodiment of multi-layer forming fabric, and this fabric has one 1 * 2 twill top surface.

Fig. 3 B is the top cutaway view of the fabric lower surface shown in Fig. 3 A.

Fig. 4 A-4F is the cutaway view of the stitching yarn of fabric shown in Fig. 3 A and the 3B.

Below with reference to accompanying drawings the present invention is made specific description more.The present invention is not subjected to the restriction of these embodiment, and on the contrary, the effect of these embodiment is to the abundant and complete open the present invention of those of ordinary skill in the art.

Described a kind of 20 and combine multi-layer forming fabric in Figure 1A and 1B, its label is 10, and shown in the figure only is a repetitive of this fabric.The repetitive of this fabric 10 comprises 10 MD top layer yarns 11-20,10 MD bottom yarn 21-30, and 10 CMD bottom yarn 31-40, and stitching yarn is to 41a, 41b--50a, 50b.

At first, wherein show a repetitive of fabric 10 bottoms with reference to Figure 1B.MD bottom yarn 21-30 and CMD bottom yarn 31-40 are with a kind of comprehensive satin weave flower type (harness satin) weave in, each root CMD bottom yarn all passes from the top of a MD bottom yarn, the below of 4 MD bottom yarns, repeats the colored type of this " last 1/ time 4 " then.For example, CMD bottom yarn 31 passes the top of MD bottom yarn 21, the below of MD bottom yarn 22-25, the top of MD bottom yarn 26 and the below of MD bottom yarn 27-30.The patterns for knitting that other CMD bottom yarn is also followed this " last 1/ time 4 ", only the CMD bottom yarn that all is adjacent of each one thread distance of 2 MD bottom yarns that staggers.Next, CMD bottom yarn 32 passes the below of

MD bottom yarn

21 and 22, the top of MD bottom yarn 23, the below of MD bottom yarn 24-27, the top of MD bottom yarn 28 and the below of MD bottom yarn 29 and 30.Like this, the below of passing CMD bottom yarn 32 by MD bottom yarn 23 forms " knot " and just departs from the distance of being passed 2 MD bottom yarns of CMD bottom yarn 31 formed " knot " by MD bottom yarn 21.

Referring now to Figure 1A, the top layer of fabric 10 by MD top layer yarns and a part of stitching yarn to constituting.As can be seen, stitching yarn combines with the MD top layer yarns and has formed a smooth flat woven top surface from Figure 1A.Interweaving of stitching yarn and MD bottom yarn and top layer yarns can be understood by reading Figure 1A and Fig. 2 A-2J.

Each root stitching yarn in the repetitive can separated into two parts: a fiber support part and a bound fraction that interweaves with a MD bottom yarn that interweaves with the MD top layer yarns.They are separated at " transition " MD top layer yarns place, and below this separation place, an one thread of stitching yarn centering passes another root stitching yarn of this yarn centering.Each all is woven together mutually to stitching yarn, to such an extent as to the fiber support of an one thread of this yarn centering partly is positioned at the top of another one thread bound fraction of this yarn centering.Each all uses label " a " expression (for example 41a, 42a, 43a) to the part of the fiber support in the stitching yarn, they are with the mode that replaces and 5 MD top layer yarns interweave (top of passing 3 MD top layer yarns that replaces and the below of 2 MD top layer yarns), another root stitching yarn of this yarn centering (representing with label " b ") then passes from the top of two MD top layer yarns, simultaneously from passing below a MD top layer yarns between these two MD yarns.In its fiber support part, each root stitching yarn all passes from the top of some MD top layer yarns, the fiber support part of adjacent stitching yarn centering is then passed from the below of these MD top layer yarns, also pass from the below of some MD top layer yarns simultaneously, the fiber support part of adjacent stitching yarn centering is then passed from the top of these MD top layer yarns.In this manner, these stitching yarns have just formed a plain weave flower type (seeing Figure 1A) with the MD top layer yarns.

At its bound fraction, each root stitching yarn all passes from the below of a MD bottom yarn with the form of repetitive.Each root stitching yarn all passes below the MD bottom yarn between formed two knots by adjacent MD, and passes the top of the CMD bottom yarn that this stitching yarn clamping is got up.The bound fraction of these stitching yarn centerings combines, and has just formed the colored type (seeing Figure 1B) of a kind of " last 1/ time 4 " on the lower surface of fabric 10.

In Fig. 2 I the tissue of stitching yarn flower type is described, it has described the situation that stitching yarn 49a, 49b and MD top layer yarns and bottom yarn interweave.In its fiber support part, stitching yarn 49a passes the top of MD

top layer yarns

11,13 and 15, and passes the below of MD top layer yarns 12 and 14.Then, it passes the below of MD transition yarn 16 and the top of MD bottom yarn 26 again.At its bound fraction, stitching yarn 49a passes the below of MD top layer yarns 17-19, pass the top of

MD bottom yarn

27 and 29 and the below of MD bottom yarn 28 again simultaneously, thereby loop bonding goes out the bottom of fabric 10.Subsequently, stitching yarn 49a passes between MD top transition yarn 20 and MD bottom yarn 30 again.Fig. 2 I has described the interleaving mode of stitching yarn 49b, and wherein, its bound fraction is positioned under the bound fraction of stitching yarn 49a; Stitching yarn 49b passes from the below of MD top layer yarns 11-15, meanwhile passes the top of

MD bottom yarn

21,22,24,25 and the below of MD bottom yarn 23 again.In its fiber support part, stitching yarn 49b passes the top of MD top layer yarns 17, the below of MD top layer yarns 18 and the top of MD top layer yarns 19, pass the below of MD transition top layer yarns 20 again, continue with linking to each other by the formed alternately tissue of stitching yarn 49a.

From Fig. 2 A-2H and 2J (they have described the colored type that other stitching yarns pair and MD bottom yarn and top layer yarns are woven into) as can be seen, above-mentioned relevant stitching yarn 49a, the colored type of 49b correlation by other stitching yarn to imitate.

Again see Figure 1A and 1B again, adjacent stitching yarn pair interweaves with MD top layer yarns and bottom yarn, make this stitching yarn between the three MD yarns of being separated by.For example, stitching yarn 41a passes from the top of MD

top layer yarns

15,17 and 19 and the below of MD bottom yarn 32.Stitching yarn 42a then passes from the top of MD

top layer yarns

12,14 and 16 and the below of MD bottom yarn 39.Like this, just be separated by three MD top layer yarns and bottom yarn of this stitching yarn 42a and stitching yarn 43a.The situation of the three MD yarns in this interval equally also is applicable to interweaving of other stitching yarns.

See Figure 1A, 1B and 2A-2J again, when stitching yarn pair combines with MD top layer yarns and bottom yarn, each root " a " yarn (passing the stitching yarn of three MD top layer yarns tops) all is positioned between two " b " yarns (passing the stitching yarn of two MD top layer yarns tops), and each root " b " yarn all is positioned between two " a " yarns.This arrangement mode by stitching yarn to 41a, 41b, 42a, 42b can reflect.Shown in Figure 1A and 1B, stitching yarn 41b is between stitching yarn 41a and 42a.As Figure 1A, shown in 1B and the 2B, stitching yarn 42a is between stitching yarn 41b and 42b.

Have now found that this configuration is influential for the Papermaking Performance of improving this fabric end face, and is especially all the more so with regard to MD transition top layer yarns.When a transition yarn passes the top of a pair of stitching yarn and forms a top surface knot, compare with other positions that it passes a stitching yarn or CMD top layer yarns top in the MD top layer yarns, will be subjected to the less supporting that makes progress that comes from stitching yarn at this knot of this position.As a result, this knot just is in than on the low slightly position of other MD top layer yarns knot.Shown in Figure 1A, the knot that is formed by transition MD top layer yarns has formed the diagonal of a series of disconnections; This cornerwise example is to pass stitching yarn 41a by MD

top layer yarns

14,41b, and 43a, 43b, MD top layer yarns 15 are passed

stitching yarn

44a, 44b, and 46a, 46b, MD top layer yarns 16 are passed

stitching yarn

47a, 47b, and 49a, 49b and MD top layer yarns 17 are passed

stitching yarn

50a, and 50b forms.May have less pressure by the formed disconnection diagonal of those MD top layer yarns knots, this is because the top less upwards cause of speaking of of supporting force.Because this knot that distributes along diagonal may be in the position that is lower than remaining MD top layer yarns knot slightly all, may show this colored type during with this fabric papermaking, the pattern that it can influence on the paper to be printed successively.Yet, because the stitching yarn that is comprised is to occur with the form that stitching yarn " a " (it passes the top of three MD top layer yarns) and stitching yarn " b " (it passes the top of two MD top layer yarns) replace, and yarn " a " and " b " depart from mutually as mentioned above, the right fiber support part of adjacent stitching yarn that is positioned near the side of MD top layer yarns knot (is for example passed by MD top layer yarns 15, the stitching yarn 46b of the below of 16 formed knots, the fiber support part of 47a) be contiguous mutually, and these yarns that are positioned at these knot opposite sides in the middle of them to (be stitching yarn 46a, fiber support part 47b) then by other stitching yarn to being spaced from each other.As a result, just be subjected to some interference by the formed diagonal of MD transition top layer yarns knot, and become not too obvious.Like this, on by fabric 10 formed paper webs, just become not too obvious, thereby alleviated the impression on the paper by the formed diagonal decorative pattern of these knots.

Those of ordinary skills are very clear, above-mentioned structure is enrolled MD top layer yarns and bottom yarn by stitching yarn and is formed in the fabric, make yarn centering " a " stitching yarn weave weaving of " b " stitching yarn of having precedence over yarn centering, and in all repetitives thereafter, keep this order.Though wish all stitching yarns to can both following this colored type,, also can obtain some benefit by changing this order, so the stitching yarn of only a small amount of (for

example percent

25,33,40 or 50) is to following this order that replaces.

Those of ordinary skills are very clear, and other plain weave flower type also can form, and wherein stitching yarn is divided into fiber support part and bound fraction in a different manner.For example, this fabric can comprise a top layer, in this top layer, each stitching yarn in its fiber support part to all from 2,3,4 or the top of more MD top layer yarns pass.These stitching yarns can pass from the top of the MD top layer yarns of different quantity, also can pass from the top of the MD top layer yarns of equal number.Certainly, also can do suitable adjustment, to change the stitching yarn flower type of its top surface to the position of the bottom knot in this stitching yarn bound fraction.

At Fig. 3 A, embodiment of another relevant multi-layer forming fabric of the present invention has been described among 3B and the 4A-4F, wherein described is that label is a repetitive in 100 the multi-layer forming fabric.This repetitive comprises 12 MD top layer yarns 101-112,12 MD bottom yarn 141-152,6 CMD bottom yarn 161-166, and 12 stitching yarn 181a, 181b-186a, 186b.

At first with reference to Fig. 3 B, by MD bottom yarn and the formed fabric 100 of CMD bottom yarn, the surface of its machine side is a kind of " interruption twill pattern ".Each root CMD bottom yarn all has a kind of flower type that repeats of " last 1/ time 5 " be made up of the MD bottom yarn.For example, CMD bottom yarn 161 passes the top of MD bottom yarn 141, the below of MD bottom yarn 142-146, the top of the top of MD bottom yarn 147 and MD bottom yarn 148-152.The colored type that remaining CMD yarn also repeats this " last 1/ time 5 ".Yet,, but be to arrange according to a kind of mode of being interrupted twill pattern by the formed bottom side of the MD bottom yarn knot that passes from the below of CMD bottom yarn, its bottom side knot is respectively by MD bottom yarn 141,143,145,142,146,144 form on CMD bottom yarn 161-166, and MD bottom yarn 147,149,151,148,152,150 form on CMD bottom yarn 161-166.As can be seen, these knots can't form a kind of tangible diagonal as TWILL CLOTH from Fig. 3 B, but form a kind of " disconnection diagonal " flower type.

As shown in Figure 3A, the top surface of fabric 100 has a kind of 1 * 2 twill flower type, and it is formed by MD top layer yarns and a part of stitching yarn.For previous described the sort of fabric 10, each root stitching yarn all has a fiber support part and a bound fraction; They are separated by the transition top layer yarns of machine direction, and a pair of stitching yarn intersects below this transition top layer yarns mutually.The colored type that the fiber support of each root stitching yarn part is all followed when interweaving with the MD top layer yarns is a kind of " on last 2/ time 1/ 2 ".At its bound fraction, except passing from the below of a MD bottom yarn, each root stitching yarn all passes between MD top layer yarns and bottom yarn.Be positioned at one or two MD yarn places by the MD bottom yarn of loop bonding, this yarn is away from the MD transition yarn that the fiber support part and the bound fraction of each root stitching yarn are separated.

This figure can be with stitching yarn 185a as example, and its loop bonding flower type is described in Fig. 4 E to some extent.Stitching yarn 185a passes the top of MD

top layer yarns

101 and 102, and the below of MD top layer yarns 103, and the top of MD top layer yarns 104,105 are passed the below of MD transition top layer yarns 106 then.At its bound fraction, stitching yarn 185a passes the top of

MD bottom yarn

147 and 148, and the below of MD bottom yarn 149, and the top of MD bottom yarn 148,149 are passed the below of MD transition top layer yarns 112 then.

Stitching yarn pair is interweaved with the MD top layer yarns, makes its fiber support part and MD top layer yarns form a kind of 1 * 2 twill flower type.Refer again to Fig. 4 E, as mentioned above, stitching yarn 185a passes the top of MD

top layer yarns

101 and 102, the below of MD top layer yarns 103, and the top of MD top layer yarns 104,105.Stitching yarn 185a, 185b pass the below of MD transition top layer yarns 106, and the fiber support of stitching yarn 185b part just continues the last 2/ time 1 twill flower type of before having been set up by stitching yarn 185a then.Like this, stitching yarn 185b passes the top of MD top layer yarns 107,108, and the below of MD top layer yarns 109, and the top of MD top layer yarns 110,111 are passed the below of MD transition top layer yarns 112 then.

What Fig. 3 A was shown is: stitching yarn and MD top layer yarns are interweaved, make " last 2 " sections in each fiber support part, " last 2 " stitching yarn sections of the stitching yarn centering that is adjacent and be positioned at this stitching yarn side departs from a MD top layer yarns.For example, stitching yarn 181a passes the top of MD top layer yarns 102 and 103.The most contiguous CMD top layer yarns 121 and 122 is passed the top of MD top layer yarns 101,102 and 103,104 respectively.Like this, the fiber support of stitching yarn part has just formed tangible 1 * 2 twill diagonal.

It is how to be interleaved in the middle of the MD bottom yarn that Fig. 3 B has also described stitching yarn.In Fig. 3 B as can be seen, the knot that forms by each root stitching yarn, when it passes the below of MD bottom yarn, the position of this knot is such: in one direction, two CMD bottom yarns pass above the CMD bottom yarn between the formed knot at the stitching yarn knot and by this MD bottom yarn, in the opposite direction, three CMD bottom yarns pass at the stitching yarn knot and by this MD bottom yarn above the CMD bottom yarn between formed another knot.For example, when stitching yarn 184a when the below of MD bottom yarn 141 is passed, just formed a knot.When MD bottom yarn 141 when the below of CMD bottom yarn 161 is passed, it has formed a knot, three CMD bottom yarns (162,163,164) are separated with itself and the formed knot of stitching yarn 184a.This colored type is also so continuity on another direction, CMD bottom yarn 165 and 166 is between the formed knot of stitching yarn 184a and another knot, this knot will be after CMD bottom yarn 166 next root CMD bottom yarn below (CMD bottom yarn 166 has the tissue flower type identical with CMD bottom yarn 161), form by MD bottom yarn 141.Like this, the stitching yarn knot of stitching yarn 184a is just separated with MD bottom yarn knot, is separated with three CMD yarns in one direction therebetween, is separated with two CMD yarns on another direction therebetween.

Those of ordinary skills are with fully aware of, and its top layer of fabric of the present invention also can adopt other forms of twill flower type.For example, this fabric can have a kind of 1 * 3 or 1 * 4 twill top layer.These twills flower types can be any colored types in traditional twill flower type, for example as fabric 100, also can adopt a kind of disconnection twill flower type, and 4 or 5 for example traditional comprehensive satin weave wovens are such.These fabrics can also constitute like this: make the fiber support of stitching yarn centering partly pass the top of varying number MD top layer yarns.Those of ordinary skills are very clear, and the bound fraction of stitching yarn all needs to do suitable variation under each situation, to adapt to the difference of fiber support part.

Those of ordinary skills are clear, though preferably describe and illustrated plain cloth and TWILL CLOTH in detail at this, but other fabric knitting mode, for example other TWILL CLOTH and SATIN AND SATEEN CLOTH, as long as it is to adopt stitching yarn pair to form a kind of papermaking surface of fabric with the MD top layer yarns, can be used.Be described as three CMD yarns of preferred employing though it is also conceivable that

fabric

10 and 100, these yarns do not pass from the below of a MD bottom yarn at least,, fabric of the present invention can comprise that also some only weigh the CMD yarn that interweaves with the MD top layer yarns.They will occupy fabric end face below percent 33 (promptly for per two concerning stitching yarn, these CMD amount of yarn are no more than), preferably occupy

percent

25 or 20 following topsheet surface, not contain any CMD yarn in the topsheet surface for best.

Can adopt any amount of fabric form, if it by stitching yarn to the MD bottom yarn is stitched together.In addition, though the right quantity of CMD top layer, bottom yarn and stitching yarn in the described fabric is identical, this is not that the present invention is necessary; Other ratio, for example two stitching yarns also can adopt corresponding CMD bottom yarn.

The structure that is used for the single yarn of fabric of the present invention can be different, and this depends on what the character of desired final papermaking fabric is.For example, this yarn can be the yarn that plurality of threads is formed, and the mono filament yarn is through the how long silk or the mono filament yarn of twisting, spun yarn, the perhaps any combination between them.In addition, the thread material that is adopted in the fabric of the present invention can be normally used various materials in the papermaking fabric now.For example, this yarn can adopt cotton, hair, polyethylene, polyester, aromatic polyamides, nylon or the like.Those of ordinary skills can be according to final fabric specifically should be used for selecting a kind of thread material.

With regard to the size of yarn, it depends on the size and the spacing of papermaking surface.In general, the diameter of MD top layer yarns is approximately equal to or less than the diameter of MD bottom yarn greatly, and the slightly larger in diameter of CMD bottom yarn is in the diameter of MD bottom yarn.In a kind of typical fabric, between 0.11-0.15mm, between 0.20-0.40mm, the diameter of MD bottom yarn is greatly between 0.17-0.25mm greatly for the diameter of CMD bottom yarn greatly for the diameter of MD top layer yarns.The diameter of stitching yarn is usually greatly between 0.11-0.17mm.

The elastic modelling quantity of yarn is preferably inequality.For example, the stitching yarn (for example yarn " b " in the fabric 10) that those outside the paired stitching yarn and a small amount of MD top layer yarns interweave, its elastic modelling quantity will be higher than paired stitching yarn (generally wanting high 10-50%).

As can be seen, fabric of the present invention is at three formable layer fabrics of the prior art from above discussion.The fabric of the present invention topsheet surface of stitching yarn as this fabric, no matter it is a plain weave, twill, satin weave or other flower types, when stitching yarn contained in the papermaking surface occupies less papermaking surface, can avoid the damage of these papermaking surfaces.The wearing and tearing that simultaneously alleviated (eliminating fully) interlayer greatly by the globality of this fabric that stitching yarn caused even fail.In addition, because this stitching yarn has constituted papermaking surface, the Tension Difference between CMD top layer yarns of the prior art and the stitching yarn no longer exists in fabric of the present invention, and this Tension Difference can make papermaking surface deform.The density of stitching yarn also makes the top layer of fabric and the combination between the bottom more complete, and when the processability of overall balance paper and durability, ABRASION RESISTANCE, it provides a kind of bigger yarn choice for the designer.

The above embodiments are to explanations more of the present invention, are not that the present invention is construed as limiting.Protection scope of the present invention depends on the equivalent that is comprised in appended claim and this claim.

Claims

1. A paper machine fabric comprising top machine direction yarns, bottom machine direction yarns, bottom cross machine direction yarns and sets of first and second cross machine direction stitching yarns, The fabric is formed in the form of several repeating units, and each repeating unit includes:

A set of machine direction top yarns;

a set of bottom yarns in the machine direction;

a set of bottom machine direction yarns interwoven with said set of bottom machine direction yarns; and

pairs of first and second stitching yarns extending in the cross-machine direction, the first and second stitching yarns in each yarn pair being aligned with said machine direction top and bottom yarns interweaving such that fiber-supporting portions of said first stitching yarns interweave with said top machine direction yarns and bonding portions of said second stitching yarns are located on said top machine direction yarns and the fiber-supporting portions of the second stitching yarns are interwoven with the top machine direction yarns, the bonding portions of the first bonding yarns are located between the top machine direction yarns Below, said first and second yarns intersect each other when passing under a machine direction transition top yarn, each joining portion of said first and second stitching yarns passing through at least one Below the underlying yarn in the root machine direction;

The fiber-supporting portion of said stitching yarns and said top machine direction yarns form a papermaking surface comprising less than 33 percent perpendicular machine direction yarns that do not pass through at least one Below the bottom yarn in the machine direction.

2. The papermaker's fabric of claim 1, wherein the fiber support portion of the first pair of alternating stitching yarns passes over the first set of machine direction alternating top yarns and the second set of machine direction yarns. direction alternating top layer yarns, and the fiber support portion in the second pair of alternating stitching yarns passes over the second set of machine direction top layer yarns and under the first set of alternating machine direction top layer yarns, said The fiber support portion of the first and second alternating stitching yarn pairs, said first set of alternating machine direction top yarns and said second set of alternating machine direction top yarns form a plain weave top surface of the fabric .

3. The papermaker's fabric of claim 2, wherein the fiber support portion of the first stitching yarns passes over the first number of machine direction yarns and the second stitching yarns The fiber support portion in passes over a second number of machine direction yarns, the first number being different from the second number.

4. The papermaker's fabric of claim 3, wherein said first number is greater than a second number, said second stitching yarns have a modulus of elasticity greater than said first seam Modulus of elasticity of the yarn.

5. The papermaker's fabric of claim 3, wherein the first number is three and the second number is two.

6. The papermaker's fabric of claim 1 wherein the diameters of the first and second stitching yarns are smaller than the diameter of the top machine direction yarns.

7. The papermaker's fabric of claim 1 wherein each joined portion of the first and second stitching yarns passes under only one machine direction bottom yarn.

8. The papermaker's fabric of claim 1 wherein said repeating unit comprises 10 top machine direction yarns and 10 bottom machine direction yarns.

9. The papermaker's fabric of claim 1 wherein said machine direction top yarns and fiber support portions of said first and second stitching yarns are interwoven in a repeating pattern Together, each fiber support portion passes over a first pair of adjacent machine direction top yarns, under a third machine direction top yarn adjacent to said first pair, and with said the second pair of machine direction top yarns adjacent to the third machine direction top yarn of A top machine direction yarn such that said top machine direction yarn, fiber support portions of the first and second stitching yarns form a 1 x 2 twill pattern.

10. The papermaker's fabric of claim 1 wherein said papermaking surface is free of vertical machine direction yarns that do not pass under at least one machine direction bottom layer yarn.

11. The papermaker's fabric of claim 1, wherein said stitching yarns interweave said machine direction top and bottom yarns such that adjacent stitching yarns The pairs are passed under the machine direction transition top yarn which is offset from the three machine direction top yarns.

12. The papermaker's fabric of claim 1, wherein 25-50 percent of the first and second stitching yarns are alternately interwoven with said top machine direction yarns .

13. A papermaker's fabric comprising top machine direction yarns, bottom machine direction yarns, bottom cross-machine direction yarns, and a set of first and second cross-machine direction stitching yarns, The fabric is formed in the form of several repeating units, and each repeating unit includes:

A set of machine direction top yarns;

a set of bottom yarns in the machine direction;

pairs of first and second stitching yarns extending in the cross-machine direction, the first and second stitching yarns in each yarn pair being aligned with said machine direction top and bottom yarns interweaving such that fiber-supporting portions of said first stitching yarns interweave with said top machine direction yarns and bonding portions of said second stitching yarns are located on said top machine direction yarns and the fiber-supporting portions of the second stitching yarns are interwoven with the top machine direction yarns, the bonding portions of the first bonding yarns are located between the top machine direction yarns Below, said first and second yarns intersect each other when passing under a machine direction transition top yarn, each joining portion of said first and second stitching yarns passing through at least one Below the bottom machine direction yarn, 25-50 percent of the stitching yarns are alternately interwoven with said top machine direction yarn;

14. The papermaker's fabric of claim 13 wherein the fibrous support portions of the first alternating pairs of stitching yarns pass over the first set of machine direction alternating top layer yarns and the second set of machine direction Underneath the alternating top layer of yarns, the fiber support portion of the second alternating pair of stitching yarns passes over the second set of machine direction top layer yarns and under the first set of alternating top layer of machine direction yarns, the first set of stitching yarns The fiber support portion of the second alternating pair, the first set of alternating machine direction top layer yarns, and the second set of alternating machine direction yarns form a plain weave top surface of the fabric.

15. The papermaker's fabric of claim 14, wherein the fiber support portion of the first stitching yarns passes over the first number of machine direction yarns and the second stitching yarns The fiber support portion in passes over a second number of machine direction yarns, the first number being different from the second number.

16. The papermaker's fabric of claim 15, wherein said first number is greater than a second number, said second stitching yarns have a modulus of elasticity greater than said first seam Modulus of elasticity of the yarn.

17. The papermaker's fabric of claim 15, wherein the first number is three and the second number is two.

18. The papermaker's fabric of claim 13, wherein the diameter of the first and second stitching yarns is smaller than the diameter of the top machine direction yarns.

19. The papermaker's fabric of claim 13, wherein each joined portion of the first and second stitching yarns passes under only one machine direction bottom yarn.

20. The papermaker's fabric of claim 13, wherein said repeating unit comprises 10 top machine direction yarns and 10 bottom machine direction yarns.

21. The papermaker's fabric of claim 13, wherein said stitching yarns interweave said machine direction top and bottom yarns such that adjacent stitching yarns The yarn pairs pass under the machine direction transition top yarns that are offset from the three machine direction top yarns.

22. The papermaker's fabric of claim 13 wherein said papermaking surface is free of vertical machine direction yarns that do not pass under at least one machine direction bottom layer yarn.

23. A method of making paper, comprising the steps of:

(a) providing a papermaker's fabric comprising top machine direction yarns, bottom machine direction yarns, bottom cross machine direction yarns, and sets of first and second cross machine direction stitchbonds Yarn, the fabric is formed in the form of several repeating units, and each repeating unit includes:

A set of machine direction top yarns;

a set of bottom yarns in the machine direction;

The fiber-supporting portion of said stitching yarns and said top machine direction yarns form a papermaking surface comprising less than 33 percent perpendicular machine direction yarns that do not pass through at least one below the bottom yarn in the machine direction;

(b) applying pulp to the fabric; and

(c) removing moisture from the pulp.

24. The method of claim 23, wherein the fiber support portion of the first pair of alternating stitching yarns passes over the first set of alternating machine direction top layer yarns and the second set of alternating machine direction top layer yarns and the fiber support portion of the second pair of alternating stitching yarns passes over the second set of machine direction top yarns and under the first set of alternating top yarns in the machine direction, said first and second The fiber support portion in alternating stitching yarn pairs, said first set of alternating machine direction top layer yarns and said second set of alternating machine direction top layer yarns form a plain weave top surface of the fabric.

25. The method of claim 23, wherein said machine direction top yarns and fiber support portions in said first and second stitching yarns are interwoven together in a repeating pattern such that Each fiber support portion passes over a first pair of adjacent machine direction top layer yarns, under a third machine direction top layer yarn adjacent to said first pair of yarns, and with said third machine direction top layer yarns. Over the second pair of machine direction top yarns adjacent to the top yarn and the fiber support portion in the adjacent stitching yarns passes over the top pair of machine direction yarns that are offset from one top machine direction pair yarn so that the machine direction top yarns, fiber support portions of the first and second stitching yarns form a 1 x 2 twill pattern.

26. The method of claim 23 wherein said papermaking surface is free of vertical machine direction yarns that do not pass under at least one machine direction bottom layer yarn.